Radiation therapy involves the use of high-energy x-rays or ionizing radiation in the treatment of malignant neoplasms and occasionally in the treatment of certain benign conditions. Depending on the type of cancer, its stage of development, its spread, and its location within the body, radiation therapy may be used as the primary curative treatment for cancer; or as an adjunctive treatment to surgery; and/or chemotherapy. The radiant energy employed during radiation therapy is thought to produce biologic change by damaging the DNA molecule of target tissues and thus hampering further effective replication of those tissues and cells. A common misconception is that therapeutic radiation severely affects malignant cells while sparing normal tissues. In actuality, the critical difference in the effect of radiation on various tissues is the ability of the normal cells and tissues to recover from radiation damage.
Two forms of radiation therapy are conventionally known: external radiation therapy (teletherapy) and internal radiation therapy (brachytherapy). External radiation therapy is administered using x-ray, gamma-ray, or electron-producing machines. Internal radiation therapy involves the insertion of radioactive isotopes directly into tumors or the tissues surrounding tumors to produce a local concentration of radiation often using appliances such as the vaginal cylinder radiation implant. The major advantage of local irradiation is that a relatively high dose of ionizing radiation can be applied to a limited anatomical area or region with accuracy and precision while protecting other tissues from potential harmful effects. Note, however, that a basic principle of radiation therapy states that the intensity of radiation is inversely proportional to the square of the distance from the radiation source (inverse square long). Thus, the proper positioning of the radioactive implant or appliance internally is of utmost importance.
The treatment of cervical cancer, uterine cancer, and vaginal cancer in the female patient are often considered as the prime examples of a successful combination of internal and external radiotherapy. External radiation therapy is usually used initially to diminish the volume of the central tumor or tumor bed area. Then, an additional dose of radiation is delivered to the tumor or designated area at greatest risk for recurrence using intracavitary or interstitial radiation devices and implants. Intracavitary implants include the vaginal cylinder radiation implant, and the tandem and colpostats. Interstitial vaginal implants include the "MUPIT" or Martinez Universal Perineal Interstitial Tool. The tandem and colpostats and MUPIT implants are inserted in the operating room under anesthesia; and are secured by suturing the labia closed or by suturing the appliance to the body.
It is estimated today that approximately 300 radioactive implant procedures are performed each year within hospitals in the greater metropolitan Boston area. All of the currently employed protocols for positioning and securing a vaginal cylinder radiation implant containing radioactive materials are makeshift and haphazard. Some hospitals rely heavily on the use of adhesive tape to immobilize the implant with the invariable consequence that the patient suffers major skin irritations and skin burning. One institution typically employs trache tape while others use adhesive tapes of various kinds. Alternatively it should be noted and appreciated also that one hospital routinely sutures the labia together to secure the implant after it has been inserted internally into the vagina. This is presently considered the most drastic and draconian procedure used today for securing a radiation implant internally.
It is useful here to briefly describe a current procedure for using a vaginal cylinder radiation implant which is to be positioned within the vagina for radiotherapy of either the vaginal wall or the cervix. The vaginal cylinder radiation implant is used most often for patients with early stage endometrial (uterine) cancer and is used less frequently for patients with cervical or vaginal cancer. These women are usually fairly healthy aside from their diagnosis of early stage localized cancer; and many have had a total abdominal hysterectomy prior to beginning the course of radiation therapy. The cylindrical implant is usually used following 5-6 weeks of daily external radiation treatments to the pelvis. The implant delivers an additional concentrated dose of radiation to the area at highest risk of recurrence of tumor while reducing the risk of bowel complications.
About two weeks after completing the external radiation treatments, the patient comes in to the hospital for an implant teaching session and pre-admission testing. The radiation oncology nurse teaches the patient about the upcoming implant procedure and gives the patient a tour of the hospital room where she will be confined during her stay.
The evening before her hospital admission, the patient begins a prepatory bowel cleanout. On admission to the hospital, a nurse completes the cleanout and inserts a foley catheter into the patient's bladder; the patient is then ready for the vaginal implant. Accompanied by the radiation oncology nurse, the physician inserts the pre-lubricated vaginal cylinder implant into the patient's vagina while the patient is lying in bed. The handle at the end of the cylinder protrudes externally from the vagina for approximately two inches after insertion. The current practice involves packing the vagina with gauze to keep the implant from moving. The outside skin around the vagina is then covered with gauze and is typically taped with elastoplast and adhesive to secure the implant. This tape is brought up to the abdomen anteriorly and the buttocks posteriorly to provide adequate support. Once the implant is taped in place, the radiation nurse and the physician leave the room, with the patient lying in bed.
Due to the radioactivity, the door to the patient's room is kept closed and visits are limited. Nurses can visit up to 30 minutes per 8 hour shift. Other visitors are limited to 30 minutes per person per day. No pregnant women or children under 18 are allowed in the room. The patient does have access to television and telephone, and books, knitting, or other diversionary things she has brought with her to occupy herself.
During the treatment, the patient must remain in bed, on her back or on her side, with her legs relatively straight. She is maintained on a clear liquid diet; has a urinary catheter in place; and is placed on anti-diarrheal medications to prevent her from having a bowel movement during the implant stay. Medications are provided if needed for anxiety and pain. Although the treatment is not considered very painful, it is often uncomfortable and many patients also experience feelings of significant isolation.
Even with the minimal movements that a patient makes lying in bed, the tape holding the implant often curls and bunches, a condition which causes skin irritation and discomfort. The nurse is limited in what she can do with the tape because the implant may become dislodged if the tape is manipulated. She may trim the end of the tape as much as is possible without jeopardizing the security of the implant; this may mitigate the discomfort but usually does not eliminate it.
Regardless of the difficulties and discomfort, it is critical that the implant remain immobilized and lodged at the chosen site. Tape has been used conventionally simply because it is freely available; however, tape takes time to put on and it presents discomfort and pain unrelated to the actual treatment for the cancer. Adjusting the tape may decrease the patient's discomfort but certainly reduces the nurse's quality time available for that patient.
After the prescribed number of radiation hours, the implant must be removed by the physician. The tape is removed first and then the implant is taken out. Removal of the implant itself is usually not painful; however, the taped area of the skin is often reddened and sore since the outer layer of skin may be taken off when the tape is removed. The irritation caused by this process may last up to two weeks, so the patient may continue to feel discomfort simply due to the means of securing the implant.
Clearly, there is a well recognized and long-standing need for alternatives and improvements in the means for securing and immobilizing a radiotherapeutic device or implant internally within the vagina. The use of tape causes skin irritation and tape burns; increases the discomfort for the patient; may cause radiation exposure to staff nurses who attempt to make the tape more comfortable for the patient; and places unnecessary demands of the attending nursing staff. Note, however, that the only presently available alternative is the suturing of the labia with the concomitant increased risk of infection and the major increase of patient discomfort. Accordingly, a garment which can be worn externally on the body and which is able to position and secure a radiotherapeutic appliance internally within the vagina would be generally recognized as a major achievement and beneficial advance in this area by both oncologists and nurses alike.